Definition of cyathium in English:


Pronunciation /sīˈaTHēəm/ /saɪˈæθiəm/


  • The characteristic inflorescence of the spurges, resembling a single flower. It consists of a cup-shaped involucre of fused bracts enclosing several greatly reduced male flowers and a single female flower.

    ‘All are tree Euphorbias, have minute sessile leaves and yellowish cyathia but differ in other respects.’
    • ‘A commonly encountered cluster of three cyathia with a mixed sexual orientation is called a cyme.’
    • ‘That means that there are plants that produce only male cyathia and others that produce only female ones.’
    • ‘In this species, there is only one nectar gland per cyathium, and petal-like appendages are lacking.’
    • ‘Inflorescences consist of a male cyathium surrounded by 5 to 7 bisexual cyathia on a short terminal branch.’


Late 19th century modern Latin, from Greek kuathion, diminutive of kuathos ‘cup’.